Broaching machine



1937. F. J. LAPOINTE 2,089,753

I BROACHING MACHINE Filed Oct. .7, 1936 2 Sheets-Sheet l Aug. 10, 1937. F. J. LAPOINTE BROACHING MACHINE Filed Oct. 7, 1936 2 Sheets-Sheet 2 Patented Aug. 10, 1937 UNITED STATES earner @FFEQE Application October '7,

1 Claim.

My invention has for its object to provide an efiicient hydraulic horizontal broaching machine that is advantageously constructed to rigidly support and guide the broach and locate the work in a position such that it may be conveniently positioned and the broach inserted therethrough and connected to the chuck of the drawbar, the parts being located to produce maximum economy of space and one that is particularly adapted to form heavy duty in broach-cutting large surface areas.

The invention may be contained in breaching machines that may be varied in their details, and to illustrate a practical application of the invention, I have selected a broaching machine containing the invention and shall describe the breaching machine selected hereinafter. The broaching machine is illustrated in the accompanying drawings.

Fig. 1 illustrates a longitudinal vertical section of the machine. Fig. 2 is a top view of the machine. Fig. 3 is an end view of the machine. Fig. 4 is a View of a section taken on the planes of the broken line 4-4 indicated in Fig. 1. Fig.

5 is a view of a section of a part of the machine taken on a plane of the line 55 indicated in Fig. l.

The particular machine shown in the drawings is provided with a frame I having a plurality of enclosing shell parts and thick wall parts that are reinforced by webbing and flanges for rigidly supporting the moving elements as against any movement other than that of the general longi tudinal movements required for efficient broaching operations. The broach is hydraulically operated by means of an oil pump 2 electrically driven by a motor 3. The oil pump 2 is located in a reservoir 4 formed in a chamber located in the lower part of the frame. A fixed piston E is supported on the end of a pipe 1 that has a relatively large diameter. The pipe I has an outlet 9 for admission of the oil from the pipe 1 into the cylinder H on one side of the piston. A pipe I2 is located within the pipe I and extends through the piston 6 and opens into the cylinder II on the other side of the piston. The pipes l and I2 are connected through a suitable base or manifold 8 and suitable pipes and a controlling valve to the reservoir 4 and to the pump 2.

The cylinder I I is provided with flanges l3 that move in ways l4 formed in inwardly projecting ribs 5 6 of thick metal that are reinforced by webs IT. The ribs I6 form a horizontally disposed, rigidly mounted guide in which the flanges l3 are 55 located for supporting the cylinder. The ways 1936, Serial No. 104,492

(Cl. Elli-3) l t are closed, and the flanges 13 are covered by means of the strips l8 that are secured to the ribs It by the machine screws E8. The flanges l3 extend substantially the length of the cylinder H, and the guide ways M extend substantially the length of the frame of the machine.

One end of the cylinder is provided with a drawhead 28 to which is connected 2. drawbar 21. The drawbar 2'? is slidably supported in a thick metal bridge 28 that extends across the top of the machine to which is secured a pair of heavy guide bars 29. The guide bars are secured to the bridge 28 and to one end of the frame of the machine that forms the work plate 3 l. The plate or end of the machine is formed of thick metal. The guide bars 29 are located on opposite sides of the drawbar 21. A chuck 32 is connected to the end of the drawbar. The chuck has a pair of bushings 33 located in thick metal winged parts 3d extending above and below the drawbar and the guide bars and through which the guide bars extend, thereby producing an exceedingly rigid structure.

The end of the machine or work plate 3i extends vertically. Its face has a vertical plane surface and has no protruding parts. It enables positioning of heavy parts to be broached in line with the chuck 32. The broach 35 is inserted through the work and the work plate into the chuck. The broach is secured in the chuck by a suitable screw clamp 36. If desired, the chuck may be provided with a threaded socket 3?, and the end of the broach may be correspondingly threaded for connecting the broach head to the chuck. The threaded screw 36 may be turned against the threaded end of the broach to prevent loosening of the broach in the machine operations. If desired, the work plate may be provided with suitable fixtures for supporting the work.

The bridge 28 is also formed of thick metal and is fitted into flange parts 38 formed on the sides 39 of the machine to securely connect the bridge to the sides by the forward draw of the guide bars, or, when clamped in position, by nuts located on threaded ends of the guide bars. The bridge may be also secured by the screws 43.

As the broach is drawn from the work, the chips are released from the cutting edges, and to prevent the chips from getting into the ways I l along which the flanges l3 of the cylinder H are moved, a suitable pan 42 is secured to the bridge 28 and to the end of the machine. The side edge parts of the pan are flanged upwardly and are secured to or fit the interior surfaces of the sides 39 of the frame of the machine. The pan thus completely covers the cylinder II and the ways that guide its movement.

The sides 39 of the frame of the machine extend to a point substantially on a level with the upper surface of the drawhead 26 and the chuck 32. The rear part of the machine is covered by means of one or more cover plates 4| so as to enclose the cylinder and the ways M, while the ways located in the part of the machine forward of the bridge 28 are covered by the pan 42. The height of the machine is such that the broach and the conditions of its teeth and the shavings produced thereby maybe readily observed by the operator, particularly as to the cutting efficiency of the broach.

I claim:

In a broaching machine, a frame having a vertical end part forming the work engaging part of the machine, a horizontally disposed cylinder having supporting flanges, ways extending length- Wise of the machine for receiving the supporting flanges, a drawhead located on the end of the cylinder remote from the said end part of the machine, a fixed piston located in the cylinder, a pair of pipes one located within the other and connected with opposite sides of the piston, a source of'supply of liquid under pressure and means for connecting the said source with the cylinder at opposite sides of the said piston to reciprocate the cylinder, the machine having a bridge part, a pair of guide bars connected to the said end of the machine and to the bridge part, a drawbar connected to the drawhead and extending over the cylinder, a chuck connected to one 1 end of the drawbar and having winged parts and sleeves through which the guide bars extend for slidably guiding the chuck and the drawbar, the said end of the machine having an opening. vfor receiving the broach.

' FRANCIS J. LAPOINTE 

